A project to advance the state of the art in automated differential leukocyte counting is proposed. The project will be both a continuation and major expansion of our previous work in which 117 leukocyte classes were differentiated in peripheral blood smears using two wide band color separation negatives, and for which a data base of over 1000 cells was assembled. As before, slide scanning rather than "flow" techniques will be used. We propose (1) to record a new and larger file or data base consisting of more than 8000 cells uniformly distributed over 38 different types, each cell recorded directly by a TV microscope system; (2) to investigate combination gradient/threshold and other new boundary finding methods; (3) to perform and record results of scene segmentation and parameter extraction for all of these cells; (4) to investigate new nuclear shape parameters to separate neutrophils (polys) from bands; (5) to investigate texture parameters for differentiating basophils and for measuring toxicity (granules); (6) to determine the effects of spectral bandwidth on color parameter discriminating power; (7) to test our overall analysis and classification system against a statistically developed standard; and (8) to extend our methodology including sample preparation, to the analysis of bone marrow smears. The resulting multispectral data base will be made widely available for research as was done with our previous data, and it will be used by us primarily for investigating image analysis algorithms. "Portability" of both the data base and algorithms is to be emphasized. The long range goals for this project are to provide sound research data for use by other basic research groups and especially for use by product-oriented groups (potential or actual manufacturers) working in the field of automated cell classification.